1. Field of the Invention
The present invention relates to an apparatus for and method of manufacturing an article of footwear having a minimal number of upper pieces. More particularly, the present invention relates to an apparatus for and method of manufacturing an athletic shoe, walking shoe, brown shoe, dress shoe or boot wherein the number of pieces required to construct the footwear upper is minimized in relation to known manufacturing processes.
2. Related Art
Shoe manufacture is a labor intensive process. The typical shoe manufacturing process encompasses the steps of cutting the upper material, reducing the thickness of the joining edges ("skiving"), reducing the thickness of the upper pieces ("splitting"), cementing the interlining to the upper pieces ("interlining"), forming the eyelets, stitching the upper pieces together, shaping the upper over a last ("lasting") and cementing, molding or sewing the bottom of the shoes to the upper ("bottoming"). Modem footwear designs, particularly athletic shoe designs, require numerous upper pieces and complicated manufacturing steps, leading to high labor costs. Additionally, a new pattern is required and the manufacturing process must be retooled for every new design and style and for each desired shoe size.
In an effort to reduce labor costs, published PCT application WO 90/03744, incorporated herein by reference, describes the use of heat embossing to minimize the number of manufacturing steps. The published application describes a process of manufacturing shoe components, including an entire one-piece upper, in which a multi-layered upper material is heat embossed in a compression mold to reduce the thickness of the material, to close or seal the edges, to incorporate a functional design or pattern lines, and for strain management. After the embossing step, the backsides of the embossed upper material are stitched together by means of a back strip and the upper material is lasted and bottomed to form the completed shoe. This process greatly reduces the cutting and stitching steps and can eliminate the skiving, splitting and interlining steps of the typical shoe manufacturing process.
However, the shoe manufacturing process disclosed in the published PCT application does not greatly reduce the assembly time and costs associated with creating new patterns and retooling the manufacturing process for new designs, new styles and different shoe sizes. Rather, a new pattern and a new embossing mold must be created for each change in design and a separate embossing mold must be used for each desired shoe size. Similarly, numerous upper materials, in varying colors and textures must be kept in inventory to accommodate desired changes in style.
What is needed therefore is an improved labor-saving and time-saving method of shoe manufacture requiring less retooling time and reduced retooling costs. Further, what is needed is an improved shoe-manufacturing method in which the required upper material inventory is reduced. Still further, what is needed is a flexible, low cost shoe-manufacturing method that can be used to form a wide variety of shoe styles and designs.